
/*开始*/
.nav_shell{
    background-color: var(--theme_color);
    color: var(--theme_text_color);
    height: 90px;
    box-sizing: border-box;
    display: flex;
    width: 100%;
    position: fixed;
    z-index: 11;
}
.nav_flex{
    display: flex;
    align-items: center;
    justify-content: space-around;
}
.nav_logo{
    width: 155px;
    height: 66.6%;
}
.nav_main{
    display: flex;
}
.nav_main li{
    margin: 0 10px;
}
.nav_search{
    height: 100%;
    width: 90px;
    display: flex;
    background-color: var(--theme_vary_color);
}
.nav_search svg{
    height: 30px;
    width: 30px;
    display: block;
    margin: auto;
}
.nav_extend_btn_flex{
    width: 90px;
    height: 100%;
    align-items: center;
    flex-direction: column;
    display: none;
}
.nav_extend_btn{
    margin: auto;
}
.nav_extend_btn span{
    display: block;
    width: 30px;
    margin: 5px 0px;
    height: 4px;
    background-color: var(--theme_vary_color);
}
.mask_layer{
    width: 100vw;
    height: 100vh;
    position: absolute;
    z-index: 8;
    background-color: rgba(0, 0, 0, 0.5);
}
@media (max-width:768px) {
    .nav_flex{
        justify-content: initial;
        flex-direction: column;
        align-items: flex-start;
    }
    .nav_extend_btn_flex{
        display: flex;
    }
    .nav_main{
        display: flex;
        position: absolute;
        top: 90px;
        z-index: 10;
        padding: 10px 0px;
        left: 0px;
        background-color: var(--theme_vary_color);
        width: 100%;
        flex-direction: column;
    }
    .nav_main li{
        padding: 10px 25px;
        color: var(--theme_color);
        font-size: 14px;
        border-bottom: 1px solid var(--usual_linea_color);
    }
    .nav_main li:hover{
        background-color: var(--usual_vary_hover_color);
    }
}
@media (max-width:500px) {
    .nav_shell{
        height: 70px;
    }
    .nav_main{
        top: 70px;
    }
    .nav_extend_btn span{
        width: 24px;
    }
    .nav_search svg{
        width: 24px;
        height: 24px;
    }
}